The present invention relates to methods and apparatus for monitoring an analogue signal.
An industrial process may be measured by a sensor. The sensor may output an analogue signal. The analogue signal may in particular comprise a series of pulses. The analogue signal may be monitored in order to determine from the analogue signal one or more properties of the industrial process. For example, the analogue signal may be monitored by counting pulses in the analogue signal.
It may be desirable to monitor the analogue signal in a failsafe manner. For example, it may be desirable to provide a method to monitor the analogue signal in a way which allows detection and diagnosis of errors in the monitoring of the analogue signal and thus delivers a high level of safety integrity.